Comment by mseebach

The trick is to abstain from all luxuries in life (thus, the "strictly need" qualifier). Of course, we don't really want to do without the luxuries, so we work to earn their cost -- and we also don't want to do without them in old age/during sickness, and so we even more to have savings. But a roof over your head and beans in your bowl, including savings for a few decades of this without working, isn't really hard to achieve at all.